I checked in the FAQs and Help sections but could not find the purpose for Realms. What are they? I did a search in this forum and a few messages mention realms and that it may be related to how long you have played the game.

Also, as the game evolves it can be a bit off-putting for a new player to look at the ranking and wonder how on earth he can get anywhere near the top. With the realms, any new player has a chance of getting to the top of any realm they are involved with as they progress.
Well, at least until they end up in Gondor :)